#! /bin/sh
#
# rc
#
# Starts/stops services on runlevel changes.
#
# Optimization: A start script is not run when the service was already
# configured to run in the previous runlevel.  A stop script is not run
# when the the service was already configured not to run in the previous
# runlevel.
#
# Authors:
# 	Miquel van Smoorenburg <miquels@cistron.nl>
# 	Bruce Perens <Bruce@Pixar.com>

PATH=/sbin:/usr/sbin:/bin:/usr/bin
export PATH

# Un-comment the following for interactive debugging. Do not un-comment
# this for debugging a real boot process as no scripts will be executed.
# debug=echo

# Specify method used to enable concurrent init.d scripts.
# Valid options are 'none', 'startpar' and 'makefile'. To enable
# the concurrent boot option, the init.d script order must allow for
# concurrency.  This is not the case with the default boot sequence in
# Debian as of 2008-01-20.  Before enabling concurrency, one need to
# check the sequence values of all boot scripts, and make sure only
# scripts that can be started in parallel have the same sequence
# number, and that a scripts dependencies have a earlier sequence
# number. See the insserv package for a away to reorder the boot
# automatically to allow this.
CONCURRENCY=none

# Make sure the name survive changing the argument list
scriptname="$0"

umask 022

on_exit() {
	echo "error: '$scriptname' exited outside the expected code flow."
}
trap on_exit EXIT # Enable emergency handler

# Ignore CTRL-C only in this shell, so we can interrupt subprocesses.
trap ":" INT QUIT TSTP

# Set onlcr to avoid staircase effect.
stty onlcr 0>&1

# Functions for splash progress bars
if [ -e /lib/init/splash-functions-base ] ; then
	. /lib/init/splash-functions-base
else
	# Quiet down script if old initscripts version without /lib/init/splash-functions-base is used.
	splash_progress() { return 1; }
	splash_stop() { return 1; }
fi

# Now find out what the current and what the previous runlevel are.

runlevel=$RUNLEVEL
# Get first argument. Set new runlevel to this argument.
[ "$1" != "" ] && runlevel=$1
if [ "$runlevel" = "" ]
then
	echo "Usage: $scriptname <runlevel>" >&2
	exit 1
fi
previous=$PREVLEVEL
[ "$previous" = "" ] && previous=N

export runlevel previous

if [ -f /etc/default/rcS ] ; then
	. /etc/default/rcS
fi
export VERBOSE

if [ -f /lib/lsb/init-functions ] ; then
	. /lib/lsb/init-functions
else
	log_action_msg() { echo $@; }
	log_failure_msg() { echo $@; }
	log_warning_msg() { echo $@; }
fi

#
# Stub to do progress bar ticks (for splash programs) on startup
#
startup_progress() {
	# Avoid divide by zero if anyone moved xdm/kdm/gdm first in a runlevel.
	if [ 0 -eq "$num_steps" ] ; then return; fi

	step=$(($step + $step_change))
	progress=$(($step * $progress_size / $num_steps + $first_step))
	$debug splash_progress "$progress" || true
}

#
# Check if we are able to use make like booting.  It require the
# insserv package to be enabled. Boot concurrency also requires
# startpar to be installed.
#
if [ "none" != "$CONCURRENCY" ] ; then
	test -s /etc/init.d/.depend.boot  || CONCURRENCY="none"
	test -s /etc/init.d/.depend.start || CONCURRENCY="none"
	test -s /etc/init.d/.depend.stop  || CONCURRENCY="none"
	startpar -v      > /dev/null 2>&1 || CONCURRENCY="none"
fi

#
# Start script or program.
#
case "$CONCURRENCY" in
	startpar|shell) # shell is obsolete
		log_action_msg "Using startpar-style concurrent boot in runlevel $runlevel"
		startup() {
			action=$1
			shift
			scripts="$@"

			# Update progress bar counter and jump to the new position
			for script in $scripts ; do
				step=$(($step + $step_change))
			done

			[ -n "$scripts" ] && $debug startpar -a $action $scripts

			# Jump back one step to compencate for stepping one
			# time too many in the for loop.
			step=$(($step - $step_change))
			startup_progress
		}
		;;
	makefile)
		log_action_msg "Using makefile-style concurrent boot in runlevel $runlevel"
		# The splash API is not handled with this CONCURRENCY mode
		startup() {
			eval "$(startpar -p 4 -t 20 -T 3 -M $1 -P $previous -R $runlevel)"

			if [ -n "$failed_service" ]
			then
				log_failure_msg "startpar: service(s) returned failure: $failed_service"
			fi

			if [ -n "$skipped_service" ]
			then
				log_warning_msg "startpar: service(s) skipped: $skipped_service"
			fi

			unset failed_service skipped_service
		}
		;;
	none|*)
		startup() {
			action=$1
			shift
			scripts="$@"
			for script in $scripts ; do
				$debug "$script" $action
				startup_progress
			done
		}
		;;
esac

# Check if the splash screen should be stopped before the given
# script.
is_splash_stop_scripts() {
	scriptname=$1
	case "$scriptname" in
		# killprocs is used in runlevel 1
		gdm|xdm|kdm|ltsp-client|ltsp-client-core|reboot|halt|killprocs)
			return 0
			;;
	esac
	return 1
}

# Is there an rc directory for this new runlevel?
if [ -d /etc/rc$runlevel.d ]
then
	# Find out where in the progress bar the initramfs got to.
	PROGRESS_STATE=0
	if [ -f /dev/.initramfs/progress_state ]; then
		. /dev/.initramfs/progress_state
	fi

	# Split the remaining portion of the progress bar into thirds
	progress_size=$(((100 - $PROGRESS_STATE) / 3))

	case "$runlevel" in
		0|6)
			ACTION=stop
			# Count down from 0 to -100 and use the entire bar
			first_step=0
			progress_size=100
			step_change=-1
			;;
		S)
			ACTION=start
			# Begin where the initramfs left off and use 2/3
			# of the remaining space
			first_step=$PROGRESS_STATE
			progress_size=$(($progress_size * 2))
			step_change=1
			;;
		*)
			ACTION=start
			# Begin where rcS left off and use the final 1/3 of
			# the space (by leaving progress_size unchanged)
			first_step=$(($progress_size * 2 + $PROGRESS_STATE))
			step_change=1
			;;
	esac

	# Count the number of scripts we need to run
	# (for progress bars)
	num_steps=0
	for s in /etc/rc$runlevel.d/[SK]*; do
		if is_splash_stop_scripts "${s##/etc/rc$runlevel.d/S??}" ; then
			break
		fi
		num_steps=$(($num_steps + 1))
	done
	step=0

	if [ makefile = "$CONCURRENCY" ]
	then
		[ "$previous" != N ] && startup stop
	# First, run the KILL scripts.
	elif [ "$previous" != N ]
	then
		# Run all scripts with the same level in parallel
		CURLEVEL=""
		for s in /etc/rc$runlevel.d/K*
		do
			# Extract order value from symlink
			level=${s#/etc/rc$runlevel.d/K}
			level=${level%%[a-zA-Z]*}
			if [ "$level" = "$CURLEVEL" ]
			then
				continue
			fi
			CURLEVEL=$level
			SCRIPTS=""
			for i in /etc/rc$runlevel.d/K$level*
			do
				# Check if the script is there.
				[ ! -f $i ] && continue

				#
				# Find stop script in previous runlevel but
				# no start script there.
				#
				suffix=${i#/etc/rc$runlevel.d/K[0-9][0-9]}
				previous_stop=/etc/rc$previous.d/K[0-9][0-9]$suffix
				previous_start=/etc/rc$previous.d/S[0-9][0-9]$suffix
				#
				# If there is a stop script in the previous level
				# and _no_ start script there, we don't
				# have to re-stop the service.
				#
				[ -f $previous_stop ] && [ ! -f $previous_start ] && continue

				# Stop the service.
				SCRIPTS="$SCRIPTS $i"
				if is_splash_stop_scripts "$suffix" ; then
					$debug splash_stop || true
				fi
			done
			startup stop $SCRIPTS
		done
	fi

	if [ makefile = "$CONCURRENCY" ]
	then
		if [ S = "$runlevel" ]
		then
			startup boot
		else
			startup $ACTION
		fi
	else
		# Now run the START scripts for this runlevel.
		# Run all scripts with the same level in parallel
		CURLEVEL=""
		for s in /etc/rc$runlevel.d/S*
		do
			# Extract order value from symlink
			level=${s#/etc/rc$runlevel.d/S}
			level=${level%%[a-zA-Z]*}
			if [ "$level" = "$CURLEVEL" ]
			then
				continue
			fi
			CURLEVEL=$level
			SCRIPTS=""
			for i in /etc/rc$runlevel.d/S$level*
			do
				[ ! -f $i ] && continue

				suffix=${i#/etc/rc$runlevel.d/S[0-9][0-9]}
				if [ "$previous" != N ]
				then
					#
					# Find start script in previous runlevel and
					# stop script in this runlevel.
					#
					stop=/etc/rc$runlevel.d/K[0-9][0-9]$suffix
					previous_start=/etc/rc$previous.d/S[0-9][0-9]$suffix
					#
					# If there is a start script in the previous level
					# and _no_ stop script in this level, we don't
					# have to re-start the service.
					#
					if [ start = "$ACTION" ] ; then
						[ -f $previous_start ] && [ ! -f $stop ] && continue
					else
						# Workaround for the special
						# handling of runlevels 0 and 6.
						previous_stop=/etc/rc$previous.d/K[0-9][0-9]$suffix
						#
						# If there is a stop script in the previous level
						# and _no_ start script there, we don't
						# have to re-stop the service.
						#
						[ -f $previous_stop ] && [ ! -f $previous_start ] && continue
					fi

				fi
				SCRIPTS="$SCRIPTS $i"
				if is_splash_stop_scripts "$suffix" ; then
					$debug splash_stop || true
				fi
			done
			startup $ACTION $SCRIPTS
		done
	fi
fi

trap - EXIT # Disable emergency handler

exit 0

